In the past, numerous systems have been suggested for controlling the heating of buildings. The most common system is the ordinary thermostatic control in which a bimetallic strip remote from the room heat source, (usually mounted on an interior wall near the center of the building) operates a switch at predetermined levels to turn the heat inlet ON and OFF.
It has been found, especially in commercial buildings, that ordinary thermostatic control is undesirable. As a consequence numerous features have been added to promote fuel efficiency and increase comfort, among which are compensation for solar radiation, night temperature setback and automatic startup. The latter features have been particularly stressed because of new requirements arising from the BOCA Code.
With electric heat, the problems of system controls are further exacerbated by utility company charges for, not only consumption, but also peak loading. Thus, while less fuel is used, the economy is not realized financially.
In the course of prepartion for the instant application a patentability search was performed having a field of search which comprised of U.S. Classifications 219/494, 236/91, and 236/46 through 49. The search uncovered the following patents:
______________________________________ U.S. Pat. No. Inventor Date of Issue ______________________________________ 4,189,094 Robinson 2/19/80 4,176,785 Allard, et al 12/4/79 4,172,555 Levine 10/30/79 4,077,566 Bradford 3/7/78 4,040,565 Christiansen 8/9/77 3,964,676 Rooks, et al 6/22/76 3,450,862 Kralovec 6/17/69 ______________________________________
Of the patents included on the search, the Kralovec patent was considered inapplicable as an indoor heat sensing element was utilized which was mounted immediately adjacent the heating element so as to sense heat output therefrom.
In the patent to Christiansen, U.S. Pat. No. 4,040,565, a mathematical equation for energy supplied to a building is derived at Column 3, line 32 and is expressed in terms of retained heat and lost heat. Christiansen attempts to define the heat capacity of a building and to construct an analog model which takes into account both the inside and outside temperatures. Christiansen is considered as teaching away from the present disclosure as the analog control thereof is taught as being not feasible without regard to inside temperature measurement.
Similarly, the other patents were analyzed and considered not to disclose the teaching of the present invention.